I reported a problem with the use of 'explain' and Pool dicts some time ago and offered a quick fix that I wasn't too sure about. Having spent a bit more time rooting around looking at the relevant code, I think it is actually a pretty good fix.
tim -- Tim Rowledge, tim@sumeru.stanford.edu, http://sumeru.stanford.edu/tim Strange OpCodes: RDLI: Rotate Disk Left Immediate